Tracking items that are popular over a period of time (trending) is a way for an online enterprise (such as a social networking system or website) to enhance user experience and keep users engaged. With a trending service, the online enterprise detects and provides trending objects for users. Trending objects are objects that are popular at a moment, at an online enterprise and/or in the physical world. A trending object can be a uniform resource locator (URL), a hashtag, a topic, a page, a subscription, an online group, a user profile, an application software, and any other entities that likely attract a user's interest and impel the users' interaction thus generate more content at the social networking system. However, at some online enterprises, millions and millions of users generate content on their own or share content with others, it is challenging to sift through the massive amount of data and identify trending objects for users.